Disc auto changer for recording or reproducing information on a desired disc of a plurality of discs in a magazine

Abstract

The speed of a disc handling operation by a disc apparatus having disc changer capability is significantly increased and, at the same time, the disc handling operation is performed with stability. In the disc apparatus according to this invention, a plurality of reproducing units loaded with discs are moved independently and disc reproduction is started by returning the reproducing units to their dedicated positions. Simultaneous returning of the plurality of reproducing units is prevented and each reproducing unit moves for refuge while reproducing the disc. This novel setup significantly shortens the time for moving the reproducing units for disc reproduction. When continuously reproducing a plurality of discs accommodated in proximity, the plurality of reproducing units are moved in a stacked state rather than independently. This also contributes to a significant reduction of the time in the disc handling operation. Further, when raising the lower reproducing unit in the stack, it is moved together with the upper reproducing unit; when raising the upper reproducing unit, it is separated from the lower reproducing unit for independent movement. This prevents the reproducing units from colliding against each other. The novel constitution significantly enhances ease of use of the disc apparatus.

What is claimed is: 
     
       1. A disc auto changer for recording or reproducing a plurality of discs comprising: a magazine for accommodating the plurality of discs;   a loader for drawing a desired disc out of said magazine and storing said disc back into said magazine;   a plurality of pickup units for recording or reproducing an information signal on said disc disposed for travel along the same axis;   a pickup unit drive for selectively moving said plurality of pickup units in independent movement and synchronous movement; and   a control circuit for controlling said pickup unit drive such that, when one of said plurality of pickup units with said loader moves to a predetermined position to perform one of operations of said loader including drawing a desired disc from said magazine and storing said disc back into said magazine, if another of said plurality of pickup units exists on a travel path of said one of said plurality of pickup units on said axis, said one of said plurality of pickup units and said another of said plurality of pickup units move synchronously to avoid a collision; if said another of the plurality of pickup units does not exist on said travel path of said one of said plurality of pickup units on said axis, said one of said plurality of pickup units moves independently.   
     
     
       2. A method of recording or reproducing on a plurality of discs of a disc auto changer which includes a plurality of pickup units for recording or reproducing an information signal to at least one of the plurality of discs, and a loader for drawing a desired disc out of a magazine and storing a disc into said magazine, the method comprising the steps of: selectively moving said plurality of pickup units along the same axis using a pickup unit drive to record or reproduce an information signal on or from a disc drawn by said loader; and   controlling said pickup unit drive such that, when one of said plurality of pickup units with said loader moves to a predetermined position to perform one of operations of said loader including drawing a desired disc from said magazine and storing said disc back into said magazine, if another of said plurality of pickup units exists on a travel oath of said one of said plurality of pickup units on said axis, said one of said plurality of pickup units and said another of said plurality of pickup units move synchronously to avoid a collision; if said another of said plurality of pickup units does not exist on the travel path of said one of said plurality of pickup units on said axis, said one of said plurality of pickup units moves independently.